Suspension system for a tracked work vehicle

ABSTRACT

A suspension system for a tracked work vehicle is provided that includes an undercarriage beam and a roller wheel beam assembly having a plurality of roller wheels and a roller wheel beam having a front clevis and a rear clevis. The suspension system also includes a front bushing mount coupled to the front clevis and a rear bushing mount coupled to the rear clevis. Moreover, the front bushing mount and the rear bushing mount are rigidly coupled to the undercarriage beam and configured to damp roll of the roller wheel beam relative to the undercarriage beam. Additionally, the suspension system includes at least one vertical mount disposed between the roller wheel beam and the undercarriage beam. Each of the at least one vertical mount is configured to provide vertical support for the roller wheel beam and to damp vertical movement of the roller wheel beam relative to the undercarriage beam.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from and the benefit of U.S. PatentProvisional Application Ser. No. 61/677,421, entitled “SUSPENSION SYSTEMFOR A TRACKED WORK VEHICLE”, filed Jul. 30, 2012, which is herebyincorporated by reference in its entirety.

BACKGROUND

The present disclosure relates generally to tracked work vehicles, andmore particularly, to a tracked work vehicle suspension system.

Certain work vehicles are moved on continuous tracks having a suspensionsystem, which includes an undercarriage beam. The undercarriage beam isused to support the vehicle above load bearing wheels (e.g., rollerwheels) rolling on the continuous track as the track moves. It isdesirable to distribute the weight of the work vehicle on the loadbearing wheels to limit damage to the continuous track due tooverheating or other weight overload issues. To achieve the weightdistribution across the load bearing wheels, certain embodiments of thesuspension dampen rotation of the wheels (e.g., roll, yaw, pitch).However, excessive movement of the suspension system components mayinduce contact between elements of the suspension system and/or the workvehicle. Additionally, it is often desirable to limit the width of thesuspension system to control the overall width of the vehicle. Forexample, if the suspension system uses a shear element to damp themovement of the wheels, and to support the vehicle, the width of thesuspension system may be wider than is desirable, and/or may not providesufficient damping of vertical motion (e.g., pitch) after extendedperiods of use.

BRIEF DESCRIPTION

In one embodiment, a suspension system for a tracked work vehicleincludes an undercarriage beam, a roller wheel assembly, a front bushingmount, a rear bushing mount, and at least one vertical mount.Additionally, the roller wheel assembly includes a plurality of rollerwheels and a roller wheel beam having a front clevis and a rear clevis.The front bushing mount is coupled to the front clevis, and the rearbushing mount is coupled to the rear clevis. The at least one verticalmount is disposed between the roller wheel beam and the undercarriagebeam. Moreover, the front bushing mount and rear bushing mount arerigidly coupled to the undercarriage beam and configured to damp roll ofthe roller wheel beam. Furthermore, each of the at least vertical mountis configured to provide vertical support for the roller wheel beam andto damp vertical movement of the roller wheel beam.

In another embodiment, a suspension system for a tracked work vehicleincludes a continuous track configured to propel the tracked workvehicle. The suspension system also includes a roller wheel beamconfigured to couple to roller wheels, and the roller wheel beamincludes at least one clevis each having at least one arm. Additionally,the suspension system includes at least one vertical mount comprising arubber pad, and the rubber pad is configured to damp vertical movementof the roller wheel beam. Moreover, the suspension system includes atleast one bushing mount. Each of the at least one bushing mountsincludes a rubber bushing configured to damp roll of the roller wheelbeam by compressing during roll of the roller wheel beam. Furthermore,each of the at least one bushing mount includes a rigid frame configuredto block roll of the roller wheel beam beyond a threshold angle byengaging a portion of the rigid frame against the at least one arm whenroll of the roller wheel beam reaches the threshold angle.

In another embodiment, a suspension system for a work vehicle includesan undercarriage beam and a roller wheel beam, which includes a clevishaving at least one arm. Additionally, the suspension system includes abushing mount coupled between the first arm and the second arm. Thebushing mount is configured to damp roll of the roller wheel beam.Moreover, the bushing mount includes a rigid frame and at least onevertical mount. The bushing mount includes at least one machined faceconfigured to block rotation of the roller wheel beam beyond a thresholdangle, a tubular bore, and a rubber bushing disposes within the tubularbore. The rubber bushing is configured to compress when the roller wheelbeam rolls. Furthermore, the at least one vertical mount is disposedbetween the roller wheel beam and the undercarriage beam, includes arubber pad, and is configured to support the undercarriage beam and dampvertical movement of the roller wheel beam.

DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a perspective view of an embodiment of a tracked work vehiclehaving a suspension system;

FIG. 2 is a perspective view of an embodiment of a suspension systemthat may be employed within the tracked work vehicle of FIG. 1;

FIG. 3 is a cross-sectional view of the suspension system shown in FIG.2;

FIG. 4 is a partially exploded perspective view of the suspension systemshown in FIG. 2;

FIG. 5 is a partially exploded perspective view of an embodiment of aroller wheel beam that may be employed within the suspension system ofFIG. 2;

FIG. 6 is an exploded perspective view of an embodiment of a pinassembly that may be employed within the suspension system of FIG. 2;

FIG. 7 is a partially exploded perspective view of the roller wheel beamand bushing mount of FIG. 5; and

FIG. 8 is a flowchart of an embodiment of a method for manufacturing anundercarriage for a tracked work vehicle.

DETAILED DESCRIPTION

One or more specific embodiments of the present disclosure will bedescribed below. In an effort to provide a concise description of theseembodiments, all features of an actual implementation may not bedescribed in the specification. It should be appreciated that in thedevelopment of any such actual implementation, as in any engineering ordesign project, numerous implementation-specific decisions must be madeto achieve the developers' specific goals, such as compliance withsystem-related and business-related constraints, which may vary from oneimplementation to another. Moreover, it should be appreciated that sucha development effort might be complex and time consuming, but wouldnevertheless be a routine undertaking of design, fabrication, andmanufacture for those of ordinary skill having the benefit of thisdisclosure.

When introducing elements of various embodiments of the presentdisclosure, the articles “a,” “an,” “the,” and “said” are intended tomean that there are one or more of the elements. The terms “comprising,”“including,” and “having” are intended to be inclusive and mean thatthere may be additional elements other than the listed elements. Anyexamples of operating parameters and/or environmental conditions are notexclusive of other parameters/conditions of the disclosed embodiments.

Various embodiments of the present disclosure include a suspensionsystem configured to damp vibrations between a track and a work vehicle.As discussed below, the suspension system uses an undercarriage beam tosuspend the vehicle over load bearing wheels, which are coupled to aroller wheel beam. The suspension system damps roll of the roller wheelbeam to enhance contact between the continuous track and the ground,even when the work vehicle is operated on uneven terrain. In the presentembodiment, the suspension system blocks roll of the roller wheel beambeyond a threshold angle to substantially reduce or eliminate thepossibility of contact between various components of the suspensionsystem/vehicle. Additionally, roll damping and limiting may be performedby bushing mounts and vertical mounts compactly placed between the armsof the roller wheel beam and the roller wheels. In certain embodiments,the roller wheel beam is compactly coupled to the bushing mounts using apin assembly. In some embodiments, the pin assembly may not extendoutwardly beyond the edges of the roller wheel beam while enabling thebushing mounts to damp roll and limit roll and/or yaw of the rollerwheel beam. In other words, the pin assembly adds no additional width tothe roller wheel beam and thereby does not widen the continuous track.Moreover, by using the compact arrangement, the bushing mounts enableroll control of the roller wheels and roller wheel beam withoutexpanding the width of the suspension system. By minimizing the width ofthe suspension system, the pin assembly and bushing mounts enable rollcontrol while enabling operation of the work vehicle in work spaces withnarrow constraints. For example, the work vehicle with narrower tracksmay be operated in a field with narrower rows of soil between vegetationwithout damaging the vegetation than a wider-tracked vehicle mayoperate. Additionally, a narrower track compacts less soil than awider-tracked vehicle, thereby leaving the field more suitablycultivated than a field on which a wider-tracked vehicle has beenoperated. Accordingly, a vehicle having a narrower track and suspensionsystem enables more efficient planting of vegetation in a field, therebyincreasing efficiency of the fields in which the vehicle is operated.

Turning now to the drawings, FIG. 1 is a perspective view of anembodiment of a tracked work vehicle 10. The vehicle 10 includes asuspension system 12 used to support the vehicle 10 and to dampvibrations between the continuous track 14 and a frame of the vehicle.As will be appreciated, a narrower track may be used to operate betweencrop rows. As discussed below, embodiments of the work vehicle 10 with anarrow track 14 may include narrower components within the suspensionsystem 12. The undercarriage beam 16 may be formed using casting,machining, and/or other suitable methods of forming the undercarriagebeam 16. Moreover, the undercarriage beam 16 may be formed from steel,iron (e.g., ductile iron), and/or other materials suitable for formationof the undercarriage beam 16 capable of supporting the vehicle 10.Additionally, the tracked work vehicle 10 has a body 18. In certainembodiments the body 18 may enclose various components used to operatethe vehicle 10. For example, in some embodiments, the body 18 mayenclose an engine, a transmission, a drive train, an exhaust system,and/or another vehicle component suitable for inclusion within thevehicle 10. In other embodiments, the vehicle 10 may have some or all ofthe suitable vehicular components exterior to the body 18. The vehicle10 further includes a driver compartment 20. In some embodiments, thedriver compartment 20 may be fully enclosed (e.g., having glass windowsall around the drive compartment 20), as illustrated. Other embodimentsmay include a driver compartment 20 that is open to the environment withor without a compartment roof. Furthermore, in certain embodiments, thedriver compartment 20 may include steering controls, a seat apparatus,temperature controls, and/or other suitable driver controls.

FIG. 2 is a perspective view of an embodiment of the suspension system12. The suspension system 12 includes a drive wheel 22 having multipledrive spokes 24 extending from its center to the perimeter of the drivewheel 22. Additionally, the continuous track 14 has multiple trackprotrusions 26 disposed along the length of the continuous track 14.Moreover, the drive wheel 22 is drivably coupled to the engine of thevehicle 10 so that the engine operation of the engine may turn the drivewheel 22 through a drive train, transmission, and/or another suitabledrive system. The drive spokes 24 rotate about the circumference of thedrive wheel 22 when the drive wheel 22 rotates. When rotating about thedrive wheel 22, a drive spoke 24 engages a respective track protrusion26 such that the rotation of the drive wheel 22 in one direction propelsthe continuous track 14 in the same direction.

The illustrated suspension system 12 further includes four idler wheels28. As discussed below, the idler wheels 28 provide tension to thecontinuous track 14 to maintain contact between the track protrusions 26and the respective drive spokes 24. Furthermore, by spacing the idlerwheels 28 at a distance relatively close to the width of the trackprotrusions 28, the idler wheels 28 provide guidance to the continuoustrack 12 to block the continuous track 12 from laterally rotating awayfrom the suspension system 12. Furthermore, although the illustratedtrack suspension 12 includes four idler wheels 22, other embodiments mayinclude 2, 3, 4, 5, 6, or more idler wheels 28.

As discussed below, a roller wheel beam 30 supports the suspensionsystem 12 by coupling with the undercarriage beam 16. The roller wheelbeam 30 also couples with multiple roller wheels 32 arranged in two rowsthat are arranged at a distance that is at least the width of the rollerwheel beam 30 and width of the protrusions. The roller wheels 32 providesupport to the suspension system and roll along the continuous track 14when the continuous track 14 is propelled around the suspension system12 by the drive wheel 22. As can be appreciated, it is desirable todistribute the weight among the roller wheels 32 or else risk damage tothe continuous track 12 and/or suspension system 12. For example, if onerow of the roller wheels 32 receives an excessive portion of the vehicleload, the continuous track 14 may overheat where the continuous track 14engages the respective row of roller wheels 32, thereby potentiallycausing damage to and/or lateral rotation of the continuous track 14. Asillustrated, certain embodiments of the suspension system 12 may include6 roller wheels 32 arranged in two rows. Other embodiments of thesuspension system 12 may include 2, 4, 6, 8, or more roller wheelsarranged in rows.

Since a width of the roller wheel beam 30 is restricted by a distancebetween the roller wheels 32 and the distance between the roller wheels32 is restricted by the width of the continuous track 14, the width ofthe roller wheel beam 30 is ultimately restricted by the width of thecontinuous track 14. Similarly, a width of the undercarriage beam 16 isultimately restricted by the width of continuous track 14 through itsrestriction of the distance between the idler wheels 28. In someembodiments, a narrow continuous track 14 is desirable, as previouslydiscussed, but a narrow width of the continuous track 14 would at leastpartially restrict the width of the undercarriage beam 16 and rollerwheel beam 30. Accordingly, in such embodiments, it is desirable to havea narrow undercarriage beam 16 and roller wheel beam 30.

FIG. 3 is a cross-section of an embodiment of the suspension system 12.As illustrated, the suspension system 12 includes a tensioning system 34disposed within the undercarriage beam 16. The tensioning system 34includes an actuator 36, overload protection system 38, and an extensionarm 40. The actuator 36 includes a piston 42 and an actuator body 44.The extension arm 40 couples to a pivot assembly 46. The pivot assembly46 includes a static pivot joint 48 and an extendable pivot joint 50each coupled to an idler wheel axle 52 via a pivot plate 54. Asdiscussed below, each pivot joint enables the idler wheel axle 52 tomove in a substantially horizontal direction according to the movementof the extension arm 40 along a longitudinal axis 56 of the extensionarm 40. Furthermore, the suspension system 12 includes a protectionplate 58 coupled to the undercarriage beam to protect the tensioningsystem 34 from dirt and other contaminants that may otherwise obstructthe operation of the actuator 36, the overload protection system 38, orthe extension arm 40.

In certain embodiments, the actuator may be a hydraulic cylinder. Insuch embodiments, the actuator body 44 may be filled with a hydraulicfluid, thereby extending the piston 42 out of the actuator body 44. Whenthe piston 42 extends, it pushes against the overload protection system38. In the illustrated embodiment, the overload protection system 38 isa coil spring configured to prevent overload of the actuator 36, butother embodiments may include other suitable overload protectionsystems, such as a hydraulic accumulators using raised weight,compressed gas, or metal bellows. Tension in the overload protectionsystem 38 exerts pressure against the extension arm 40 thereby extendingthe arm 40 away from the actuator 36. As the extension arm 40 extends inthe longitudinal direction 56, the extendable pivot joint 52 moves inthe same direction, thereby enabling the idler wheel axle 52 to move inthe same direction. As can be appreciated, by extending the extensionarm 40 at a desired pressure, the continuous track 14 may be loaded witha desired tension to block lateral rotation of the continuous track 14during operation of the vehicle 10.

Additionally, suspension system 12 includes a front bushing mount 60 anda rear bushing mount 62 used to couple the roller wheel beam 30 to theundercarriage beam 16, as discussed below. Further, the suspensionsystem 12 includes multiple vertical mounts 64. The vertical mounts 64enable the undercarriage beam 16 to support a vertical load (e.g.,weight of the vehicle 10) and to absorb vertical movement of the rollerwheel beam 30 during operation of the vehicle 10. Additionally, theillustrated embodiment of the suspension system 12 includes two verticalmounts, but other embodiments may include 0, 1, 2, 3, or more verticalmounts.

FIG. 4 is a partially exploded view of the suspension system 12.Specifically, the undercarriage beam 16, roller wheel beam 30, frontbushing mount 60, rear bushing mount 62, and vertical mounts 64 areshown. For the purposes of discussion reference may be made to alongitudinal direction 66, an axial direction 68, and a verticaldirection 70 with respect to the roller wheel beam 30 and undercarriagebeam 16. Reference may also be made to a pitch direction 71, a rolldirection 72, and a yaw direction 73 for the suspension system 12.

In certain embodiments, the front bushing mount 60 is coupled to theundercarriage beam 16 via front mount bolts 74 and is also coupled tothe roller wheel beam 30 via a front pin assembly 76, and the rearbushing mount 62 is coupled to the undercarriage beam 16 via rear mountbolts 75 and is also coupled to the roller wheel beam 30 via a rear pinassembly 78. Other embodiments may couple the front bushing mount and/orthe rear bushing mount 62 to the undercarriage beam 16 using weldingconnection, brackets, braces, or other suitable connections. Asdiscussed in detail below, the pin assemblies 76, 78 compactly couplethe roller wheel beam 30 to a respective bushing mount 60, 62, therebyenabling a compact placement of the roller wheels 32. Moreover, thecoupling between the bushing mounts 60, 62 and the roller wheel beam 30damps movement of the roller wheel beam 30 in the roll direction 72 andlimits movement of the roller wheel beam 30 in the roll direction 72 andthe yaw direction 73.

Each vertical mount 64 includes a lower pad 80, a rubber pad 82, and anupper pad 84. In certain embodiments, the width of the lower pad 80 andthe upper pad 84 in the axial direction 68 is equal to a width of theroller wheel beam 30 in the axial direction 68. In other embodiments,the width of the lower pad 80 and the upper pad 84 may be greater thanor equal to the width of the roller wheel beam 30 in the axial direction68. Moreover, the lower pad 80 has two lower flanges 86 that extenddownwardly in the vertical direction 70 on opposite ends of each lowerpad 80. The lower flanges 86 have a width in the longitudinal direction66 that is less than or substantially equal to a width of a roller wheelbeam notch 88 in the longitudinal direction 66. The roller wheel beamnotch 88 is formed into the roller wheel beam 30 such that the notch 88may receive the lower pad 80 until the lower pad 80 is planar with thelateral and upper faces of the roller wheel beam 30. In other words, theroller wheel beam notch 88 may be substantially the same size and shapeas the lower pad 80.

As can be appreciated, the wheel beam notch 88 blocks the vertical mount64 from moving in the longitudinal direction 66, and the lower flanges86 block movement of the vertical mount 64 in the axial direction 68.Similar to the lower pad 80, the upper pad 84 has two upper flanges 90located on opposite ends of the upper pad 84. The upper flanges 90extend upwardly in the vertical direction 70 having a width in thelongitudinal direction 66 that less than or substantially equal to thewidth of a notch in the undercarriage beam 16. The undercarriage beamnotch secures the upper pad 84 relative to the undercarriage beam 16 toblock movement of each respective vertical mount 64 in a manner similarto the roller wheel beam notch 88 securing the lower pad 80. Thevertical mounts 64 also include a rubber pad 82. The rubber pad 82provides support for the undercarriage beam 16 and enables the rollerwheel beam 30 to move in the vertical direction 70 while damping themovement in the vertical direction 70 thereby reducing the movementtransmitted to the undercarriage beam 16 and ultimately the remainder ofthe vehicle 10 (e.g. driver compartment).

FIG. 5 is a partially exploded perspective view of the roller wheel beam30, front bushing mount 60, and rear bushing mount 62 of the suspensionsystem 12. The roller wheel beam 30 has a front clevis 100 and a rearclevis 102. Each clevis has a first arm 104 and a second arm 106. Thefirst arm 104 has a first opening 108, and the second arm has a secondopening 110. In certain embodiments, the first opening 108 and/or thesecond opening 110 may have an annular shape, a polygonal shape, acombination thereof, or any other suitable shape. Additionally, in someembodiments, the openings may vary in size relative to one another. Thefirst arm 104 also includes a first recess that is located on anexterior face of the roller wheel beam 30 and concentric with the firstopening 108. In some embodiments, the first recess may be cylindrical,polyhedral, or another shape (e.g., obround). Similarly, the second arm106 includes a second recess 112 located on an exterior face of theroller wheel beam 30 and concentric with the second opening 110. Theillustrated embodiment of the second recess 112 is obround, but otherembodiments of the second recess 112 may be cylindrical, polyhedral, oranother shape. In certain embodiments, it may be desirable to form thesecond opening 110 and/or the second recess 112 into a shape that blocksrotation of a pin within the second opening 110. Moreover, each arm 104,106 may include a machined section 114 on an inner surface of the armabout a respective opening 108, 110 to enable rotation of a bushing incontact with the arms.

The illustrated embodiment of the suspension system 12 further includesthe front bushing mount 60 and the rear bushing mount 62. Each bushingmount 60, 62 includes a frame 116 formed from a rigid material (e.g.,steel, ductile iron, etc.) suitable for mounting the bushing mount 60,62 to the undercarriage beam 16. In certain embodiments, the frame 116may provide additional support to the undercarriage beam 16, and may becoupled to the undercarriage beam using front and rear mount bolts 74,75. In other embodiments, the rigid frame 116 may be coupled to theundercarriage beam 16 by brackets, braces, welded connections, oranother suitable coupling. Furthermore, the rigid frame 116 includes aframe opening 118 that extends through the rigid frame 116. In certainembodiments, the frame opening 118 may have a cylindrical or annularshape. However, other embodiments may include frame openings 118 havinga polyhedral shape. Moreover, each bushing mount 60, 62 includes abushing 120 disposed within the frame opening 118. In some embodiments,the bushing 120 may be formed from rubber or other resilient materialssuitable for compression within the frame opening 118. Additionally, theshape of the bushing 120 may be selected to correspond to the frameopening 118.

Each bushing 120 may include one or more cutouts 122. The number, size,location, and shape of the cutouts 122 may be selected to achieve adesired resistance to compression in each direction. For example, toenable more compression of the bushing 120, the bushing 120 may includeadditional cutouts 122 or cutouts having an increased size.Alternatively, the bushing 120 may include fewer cutouts 122, and/orsmaller cutouts 122 to reduce the compressibility of the bushing 122.Accordingly, various embodiments of the bushing 122 may include 0, 1, 2,3, 4, or more cutouts 122 with various locations, sizes, and shapesselected according to the desired compressibility of the bushing 120.Furthermore, each bushing 120 includes a bushing opening 124 thatextends through the bushing 120. An interior bushing 126 is locatedwithin the bushing opening 124. The interior bushing 126 may be formedfrom steel, iron, or another suitable rigid material. In someembodiments, the interior bushing 126 may be bonded to the bushing 122(e.g., using an adhesive or a material connection). Additionally, theinterior bushing 126 may extend beyond the bushing 120 on either lateralside of the bushing opening 124, thereby enabling rotation of theinterior bushing 126 even when the interior bushing 126 abuts themachined portion 114. The interior bushing 126 includes an interiorbushing opening 128 that extends through the interior bushing 126.Additionally, the interior bushing 126 may have an annularcross-section, a rectangular cross-section, or anycylindrical/polyhedral cross-section having an interior bushing opening128. Moreover, the bushing opening 124 may be any shape corresponding tothe shape of the interior bushing 126 so that the wall of the interiorbushing 126 engages the wall of the bushing opening 124.

The suspension system 12 further includes pin assemblies 76, 78 that areeach configured for insertion into a respective opening within arespective bushing mount 60, 62. Each pin assembly 76, 78 includes afirst pin 130, a second pin 132, and a pin bolt 134. As discussed indetail below, the first pin 130 is inserted through the first opening108 and into the interior bushing opening 128 (or the bushing opening124 if an embodiment of the suspension system 12 does not include theinterior bushing 126). Furthermore, the second pin 132 is insertedthrough the second opening 110 and into the interior bushing opening 128(or the bushing opening 124 if the interior bushing 126 is omitted froman embodiment).

As illustrated in FIG. 6, the first pin 130 includes a first annularopening 136, a first pin head 138, and a first chamfered end 140.Furthermore, the first annular opening 136 extends through the entirefirst pin 130 along a longitudinal axis 142 of the pin assembly 76, 78.The second pin 132 has a second annular opening 144 along thelongitudinal axis 142, a second pin head 146, and a second chamfered end148. The second annular opening 144 extends into the second pin 132 andhas a threaded portion 150. In some embodiments, the second annularopening 144 extends through the entire second pin 132 and the head 146.In other embodiments, the second annular opening 144 only extendsthrough a portion of the second pin 132. Additionally, certainembodiments may include a threaded portion 150 that extends along theentire length of the second annular opening 144, but other embodimentsmay include a threaded portion 150 that only extends along a portion ofthe second annular opening 144.

As will be appreciated, because the bushing 120 is composed of aresilient material, the bushing 120 may rotate within the frame opening118, thereby skewing alignment of the interior bushing opening 128 withthe first opening 108 and the second opening 110. To facilitate thealignment of the interior bushing opening 128 with the first opening 108and the second opening 110, each pin has a chamfered end configured tofacilitate insertion of the pin into the interior bushing opening 128.Specifically, the first pin 130 has a first chamfered end 140 thatenables the first pin 130 to be inserted into the first opening 108 anda first end of the interior bushing opening 128. Similarly, the secondpin 132 has a second chamfered end 148 that enables the second pin 132to be inserted into the second opening 110 and a second end of theinterior bushing opening 128. As will be appreciated, by inserting bothpins 130, 132 into respective openings (e.g., the first opening 108)using a chamfered end (e.g., first chamfered end 140), the pinsfacilitate further alignment of the interior bushing opening 128 witheach respective opening 108, 110. Furthermore, in certain embodiments,the first pin 130 and the second pin 132 may contact each other withinthe interior bushing opening 128. Other embodiments may include a gapbetween the first pin 130 and the second pin 132 when the pins areinserted into the interior bushing opening 128.

Additionally, each pin 130, 132 includes a pin head 138, 146 that fitsinto the respective recess on the roller wheel beam 30 such that eachpin head does not extend beyond the exterior surface of the roller wheelbeam 30. For example, the first pin head 138 is fully inserted into thefirst recess in the roller wheel beam 30 such that the first pin head146 does not extend out from the first recess when the first pin 130 isinserted into the first opening 108. Similarly, the second pin head 138is fully inserted into the second recess 112 such that the second pinhead 146 does not extend out from the second recess 112 when the secondpin 132 is inserted into the second opening 112. In other words, thepins 130, 132 do not increase the width of the roller wheel beam 30 wheninserted into their respective openings.

To enable the insertion of each pin head into the respective recess,each pin head may be formed into a shape that corresponds to the shapeof the respective recesses. Accordingly, the pin heads 138, 146 may beformed into any polyhedral shape, cylindrical shape, or any othersuitable shape. For example, the illustrated embodiment of the pinassembly 76, 78 include an obround-shaped second pin head 146 that maybe inserted into the similarly obround-shaped second recess 112.Similarly,—the cylindrical shaped first pin head 138 may be insertedinto a similarly shaped first recess. In some embodiments, the pin heads138, 148 may have a depth that is equal to or less than the depth of therespective recess. In other words, each pin head may be planar with arespective laterally outward surface of the roller wheel beam 30, or maybe recessed within the laterally outwards surface of the roller wheelbeam 30. As may be appreciated, having each pin 130, 132 recessed in orplanar with the sides of the roller wheel beam, the pins may notinterfere with operation of the roller wheels 32 when the pins are fullyinserted into the roller wheel beam 30. In addition, the pins do notextend the width of the roller wheel beam 30 and/or the continuous track14.

The bolt 134 includes a bolt head 152 having a driving section 154. Incertain embodiments, the driving section 154 includes a hexagonal shapedrecess suitable for driving the bolt 134 in rotation. However, otherembodiments may include other suitable arrangements of driving the bolt134 (e.g., Phillips type drive). Further, a radius of the bolt head 152is smaller or equal to a radius of the first annular opening 136. Bylimiting the diameter of the bolt head 152 to the diameter of the firstannular opening 136, the bolt 134 may be fully inserted into the firstpin 130, thereby substantially reducing or eliminating the possibilityof interference with operation of the roller wheels 32. The bolt 134further includes a shaft 156 having multiple threads 158. In someembodiments, the threads 158 may extend along the full length of theshaft 156. In other embodiments, the threads 158 may extend only aportion of the length of the shaft 156. The threads 158 correspond tothe threaded portion 150 of the opening 144 such that the threadedportion 150 engages the threads 158 when the bolt 134 is inserted intothe second pin 132. Specifically, after the first pin 130 is insertedinto the first opening 108 and the second pin 132 is inserted into thesecond opening 110, the bolt 134 may be inserted through the firstannular opening 136 and into the second annular opening 144 such thatthe threads 158 engage the threaded portion 150. Accordingly, the bolt134 secures the first pin 130 and the second pin 132 thereby securingthe bushing mount to the roller wheel beam 30.

FIG. 7 is a partially exploded perspective view of the roller wheel beam30 and the bushing mounts 60, 62, illustrating an embodiment of acompression bolt 160. As will be appreciated, the vertical mounts 64 mayinterfere with the vertical alignment of the interior bushing openings128 and the first and second openings 108, 110 because to the height ofthe uncompressed vertical mount 64 is greater than the desired finaldistance between the roller wheel beam 30 and the undercarriage beam 16.However, the resilient pad 82 may be compressed to facilitate verticalalignment of the interior bushing opening 128 with the first and secondopenings 108, 110. In the illustrated embodiment, the roller wheel beam30 includes a compression slot 162. The compression slot 162 may bealigned with a bolt receiver 164 in the rigid frame 116, which hasthreads configured to engage corresponding threads on the compressionbolt 160. When each bushing mount 60, 62 is properly aligned with theroller wheel beam 30, the compression bolt 160 may be inserted throughthe compression slot 162 and into the bolt receiver 164. As thecompression bolt 160 is rotated, the roller wheel beam 30 is drivencloser to the undercarriage beam 16, thereby compressing the verticalmounts 64. After the compression bolt 160 is rotated to substantiallyalign the interior bushing opening 128 with the first opening 108 andthe second opening 110, the pins may be inserted into the respectiveopenings Furthermore, in some embodiments, after the pins 130, 132 areinserted through respective openings and secured using the bolt 134, thecompression bolts 160 may be removed.

FIG. 8 is a partially exploded perspective view of a bushing mount 60,62 including a roll angle limiting system 200. As the roller wheel beam30 rotates in the roll direction 72, the first arm 104, the second arm106, and the pin assemblies 76, 78 are urged to rotate in the same rolldirection 72. The bushing mount 60, 62 resists the rotation bycompressing at least some portion of the bushing 120. As previouslydiscussed, the cutouts 122 may be particularly selected to achieve adesirable amount of compression resistance. For example, if a highercompression resistance is desired the size and/or number of cutouts 122may be reduced. Furthermore, if a lower level of compression resistanceis desired, the size and/or number of cutouts 122 may be increased.Additionally or alternatively, the material used to form the bushing 120(e.g., rubber) may be selected to achieve a desired compressibility.

Moreover, a roll limiting system 200 may be included to limit the rollangle of the roller wheel beam 30 in relation to the undercarriage beam16 and/or bushing mounts 60, 62. Specifically, the roll angle limitingsystem 200 includes an upper angular portion 202, vertical section 204,and a lower angular portion 206. These portions may be located on bothlateral sides of each bushing mount 60, 62. In certain embodiments, theupper angular portion 202 and/or lower angular portion 204 may be formedby machining the bushing frame 116 to establish substantially flat andangularly accurate surfaces. Each angular portion is configured to blockroll of the roller wheel beam 30 via contact between the angular portionand an inner surface of a respective clevis arm. For example, the firstarm 104 may rotate in the roll direction 72 until the first arm 104engages the upper angular portion 202. When the arm engages an angularportion, the resulting contact blocks rotation of the roller wheel beam30 in the roll direction 72. In addition, the roll limiting system 200enables rotation of the roller wheel beam 30 in the roll direction 72due to a gap created between each angular portion and the respectiveclevis arm, thereby facilitating rotation in the roll direction 72 untilthe roller wheel beam 30 reaches a threshold angle. Additionally, incertain embodiments, the roll limiting system 200 may include thresholdangles of 1, 2, 3, 4, 5, 6, 7, 8, or more degrees. In some embodiments,the upper angular portion 202 and the lower angular portion 206 mayestablish the same threshold angle (e.g., less than 6 degrees). Otherembodiments may include an upper angular portion 202 and a lower angularportion 206 configured to establish different threshold angles (e.g.,upper angle of 5 degrees and a lower angle of 6 degrees) to facilitateasymmetrical rotation of the roller wheel beam. Alternatively,embodiments having differing threshold angles may accommodate rollerwheel beams that have shapes other than a rectangular solid.

Furthermore, the roll limiting system 200 may block rotation of theroller wheel beam 30 in the yaw direction 73. Specifically, as theroller wheel beam 30 is urged to rotate in the yaw direction 73, theroller wheel beam 30 is blocked by contact between the middle section204 and the first arm 104 or the second arm 106. In some embodiments,the bushing mounts may be configured to enable the roller wheel beam torotate in the yaw direction 73 until a yaw threshold angle is reached.In certain embodiments, the yaw threshold angle may be 0, 0.25, 0.5,0.75, 1, 1.25, 1.5, or more degrees. As will be appreciated, the yawthreshold angle may be altered by modifying a width of the bushing mount60, 62 at the middle section 204. For example, the yaw threshold anglemay be increased by decreasing the width of the bushing mount 60, 62 atthe middle section 204.

As will be appreciated, by locating the pin assemblies 74, 76 andbushing mounts 60, 62 between the roller wheels 30, the suspensionsystem 12 enables roll angle dampening and limitation without addingadditional width to the suspension system 12 and the continuous track14. Additionally, the vertical mounts 64 enable the suspension system 12to damp movement in the vertical direction 70 (e.g., movement in thepitch direction 71), and enable the suspension system 12 to supportvertical loads. Moreover, the vertical mounts 64 enable the suspensionsystem 12 to damp vertical movement, and to support vertical loadswithout adding additional width to the suspension system 12 and thecontinuous track 14. Accordingly, a work vehicle 10 incorporating thedisclosed suspension system 12 enables the work vehicle 10 to be used innarrower locations, among crops arranged in narrower rows, and/or inapplications where reduced soil compaction is desired. Furthermore, awork vehicle incorporating the disclosed suspension system 12 enablesthe work vehicle 10 to allow for a smoother ride and enhanced tracklongevity.

While only certain features and embodiments of the invention have beenillustrated and described, many modifications and changes may occur tothose skilled in the art (e.g., variations in sizes, dimensions,structures, shapes and proportions of the various elements, values ofparameters (e.g., temperatures, pressures, etc.), mounting arrangements,use of materials, orientations, etc.)) without materially departing fromthe novel teachings and advantages of the subject matter recited in theclaims. It is, therefore, to be understood that the appended claims areintended to cover all such modifications and changes as fall within thetrue spirit of the disclosure. Furthermore, in an effort to provide aconcise description of the embodiments, all features of an actualimplementation may not have been described (i.e., those unrelated to thepresently contemplated best mode of carrying out the disclosure, orthose unrelated to enabling the claimed disclosure). It should beappreciated that in the development of any such actual implementation,as in any engineering or design project, numerous implementationspecific decisions may be made. Such a development effort might becomplex and time consuming, but would nevertheless be a routineundertaking of design, fabrication, and manufacture for those ofordinary skill having the benefit of this disclosure, without undueexperimentation.

The invention claimed is:
 1. A suspension system, for a tracked workvehicle, comprising: an undercarriage beam; a roller wheel assemblycomprising a roller wheel beam having a front clevis and a rear clevis,and a plurality of roller wheels rotatably coupled to the roller wheelbeam; a front bushing mount coupled to the front clevis, and a rearbushing mount coupled to the rear clevis, wherein the front bushingmount and the rear bushing mount are rigidly coupled to theundercarriage beam, and configured to damp roll of the roller wheel beamrelative to the undercarriage beam, each bushing mount comprising abushing frame having a bore, and a resilient bushing disposed within thebore, the bushing frame rigidly coupled to the undercarriage beam, andthe resilient bushing resiliently coupled to a respective clevis; and atleast one vertical mount disposed between the roller wheel beam and theundercarriage beam, the at least one vertical mount comprising: a firstpad configured to engage a first notch in the undercarriage beam,wherein the first pad comprises two first flanges that extend upwardlyand are located at opposing lateral ends of the first pad; a second padconfigured to engage a second notch in the roller wheel beam, whereinthe second pad comprises two second flanges that extend downwardly andare located at opposing lateral ends of the second pad; and a resilientpad disposed between the first and second pads, wherein the resilientpad is configured to damp vertical movement of the roller wheel beamrelative to the undercarriage beam, wherein the at least one verticalmount is configured to provide vertical support for the roller wheelbeam, and to damp vertical movement of the roller wheel beam relative tothe undercarriage beam.
 2. The suspension system of claim 1, wherein thefirst flanges engage opposing lateral faces of the undercarriage beam toorient the vertical mount in relation to the undercarriage beam, and thesecond flanges engage opposing lateral faces of the roller wheel beam toorient the vertical mount in relation to the roller wheel beam.
 3. Thesuspension system of claim 1, wherein the bushing frame comprises: afirst face in facing relation with an inner surface of a first arm of arespective clevis, wherein the first face comprises: a first upperangular portion angled away from the inner surface of the first arm at athreshold angle; a first middle portion oriented substantially parallelto the inner surface of the first arm; and a first lower angular portionangled away from the inner surface of the first arm at the thresholdangle; a second face in facing relation with an inner surface of asecond arm of the respective clevis, wherein the second face comprises:a second upper angular portion angled away from the inner surface of thesecond arm at the threshold angle; a second middle portion orientedsubstantially parallel to the inner surface of the second arm; and asecond lower angular portion angled away from the inner surface of thesecond arm at the threshold angle.
 4. The suspension system of claim 3,wherein the bushing frame is configured to block roll of the rollerwheel beam beyond the threshold angle, via contact between the angularportions and the respective inner surfaces.
 5. The suspension system ofclaim 4, wherein the threshold angle is less than 6 degrees.
 6. Thesuspension system of claim 3, wherein the first middle portion isconfigured to engage the inner surface of the first arm, and the secondmiddle portion is configured to engage the inner surface of the secondarm to substantially block yaw of the roller wheel beam relative to theundercarriage beam.
 7. A suspension system for a work vehicle,comprising: a roller wheel beam comprising a clevis, wherein the clevisincludes a first arm and a second arm; a bushing mount resilientlycoupled to the clevis between the first arm and the second arm, whereinthe bushing mount comprises: a bushing frame having a bore and at leastone face configured to block rotation of the roller wheel beam beyond athreshold angle via contact between the at least one face and an innersurface of a respective arm of the clevis; a resilient bushing disposedwithin the bore, and configured to damp roll of the roller wheel beamvia compression of the resilient bushing; and at least one verticalmount disposed between the roller wheel beam and an undercarriage beam,the at least one vertical mount comprising: a first pad configured toengage a first notch in an undercarriage beam, wherein the first padcomprises two first flanges that extend upwardly and are located atopposing lateral ends of the first pad; a second pad configured toengage a second notch in the roller wheel beam, wherein the second padcomprises two second flanges that extend downwardly and are located atopposing lateral ends of the second pad; and a resilient pad disposedbetween the first and second pads, wherein the resilient pad isconfigured to damp vertical movement of the roller wheel beam relativeto the undercarriage beam, wherein the at least one vertical mount isconfigured to support the undercarriage beam, and to damp verticalmovement of the roller wheel beam relative to the undercarriage beam. 8.The suspension system of claim 7, comprising a pin assembly configuredto resiliently couple the bushing mount to the clevis.
 9. The suspensionsystem of claim 7, wherein the bushing frame comprises: a first face infacing relation with an inner surface of the first arm, wherein thefirst face comprises: a first upper angular portion angled away from theinner surface of the first arm at a threshold angle; a first middleportion oriented substantially parallel to the inner surface of thefirst arm; and a first lower angular portion angled away from the innersurface of the first arm at the threshold angle; a second face in facingrelation with an inner surface of the second arm, wherein the secondface comprises: a second upper angular portion angled away from theinner surface of the second arm at the threshold angle; a second middleportion oriented substantially parallel to the inner surface of thesecond arm; and a second lower angular portion angled away from theinner surface of the second arm at the threshold angle.
 10. Thesuspension system of claim 9, wherein the threshold angle is less than 6degrees.
 11. The suspension system of claim 9, wherein the first middleportion is configured to engage the inner surface of the first arm, andthe second middle portion is configured to engage the inner surface ofthe second arm to substantially block yaw of the roller wheel beamrelative to the undercarriage beam.
 12. The suspension system of claim7, wherein the resilient bushing comprises a plurality of cutoutsconfigured to vary a compressibility of the resilient bushing.
 13. Thesuspension system of claim 7, wherein the bushing frame is formed from amaterial comprising ductile iron.